Answer:
E) A, B, and C
Explanation:
Syn addition refers to the addition of two substituents on the same face or side of a double bond. This differed from anti addition which a occurs across opposite face of the double bond.
Hydrogenation, hydroboration and dihydroxylation all involve syn addition to the double bond, hence the answer chosen above.
 
        
             
        
        
        
A physical property is a quality or condition of a substance that can be observed or measured without changing the substance's composition. a chemical property is the ability of a substance to undergo a specific chemical change.
        
             
        
        
        
The correct one is Respiratory Distress !! 
As rest are not concerned with air pollution !!
        
                    
             
        
        
        
N₂ + 3H₂ ⇒ 2NH₃
doesnt matterN₂ + 6.64H₂ ⇒ 2NH₃
(6.64H₂/3H₂) x (2NH₃) =4.4266667
rounded to sig figs= 4.43